A simple method to determine crack opening stress for the center cracked plate under cyclic tensile loads

A new approach is proposed to determine crack opening stress (COS) on the basis of the variable quantity of maximum crack opening displacement (VMCOD). Based on elastic-plastic finite element analysis of center cracked finite plate, and accounting for the effects of crack geometry size, stress R-ratio, Young's modulus, yield stress and strain hardening, the explicit expression of relationship between COS and VMCOD is presented. This method avoids adopting parameters around crack tip and also is applicable to large-scale yielding state. Further studies show this relationship could be applied to predict crack growth rates, which correlate well with experimental results.